Yes, as long as the external store where the product was purchased accepts its return.
Once the product is delivered you must mark it as received, but before marking it as reviewed, you must assess whether you want to return it. If you are clear that you want to return the product, the ideal is to start the return process, contacting the proponent, before marking the product as reviewed. That way you can open a dispute if you have problems with the return. You can also start the return process after the escrow funds have been transferred to the proponent, but you will need their collaboration to proceed with the return.
The return can be managed by the proponent in the external store, or he can assign you the rights for the return in the external store if it allows it. For example, Amazon accepts another user manages the return if he presents a gift ticket for the product, which you can request from the proponent. The way in which the return is managed is something that you will have to discuss with the proponent.
We are working on offering a better service in terms of returns. In the meantime, we recommend that if you need a new escrow, reuse the escrow of the agreement through custom transactions. That way you can open a dispute if the return process goes wrong, and Bitgree can review it.